Eats on the way from NYC to PIT?
There's a bunch of restaurants near the Pgh airport - off I-279 (Parkway West) near Robinson Town Center. You'll be, oh, 10-15 min from the airport (locals, please forgive/correct me, I grew up in the eastern 'burbs). Last time I was there, food options included Quaker Steak and Lube and Max and Erma's (both sit-down), as well as some fast food.
Charlie's while reccomended and unique, will not be quick. All hot dogs are grilled to order.
A quicker (albeit not as good )dog place would be yocco's off the route 100 exit of I78 west of Allentown.
On your way back Dietrich's meatsin Krumsville (visible from I-78) is highly reccomended for sausage and other Pennsylvania Dutch items. www.dietrichsmeats.com